1. Field
The present invention relates to a rechargeable battery, and more particularly, to a separator finishing structure of a laminate type of electrode assembly.
2. Description of the Related Technology
A rechargeable battery differs from a primary battery in that it can be repeatedly charged and discharged, while the latter can only irreversibly convert chemical energy to electrical energy. A low-capacity rechargeable battery is typically used as a power supply for small electronic devices, such as cellular phones, notebook computers, and camcorders, while a high-capacity rechargeable battery is typically used as a power supply for driving motors in hybrid vehicles and the like.
A rechargeable battery generally includes an electrode assembly with a positive electrode plate, a separator, and a negative electrode plate, and a case receiving the electrode assembly. The case is formed with a cylindrical or prismatic metal can, or with a laminate sheet having a resin sheet layer and a metal sheet layer. The electrode assembly may be formed as a spiral-wound type or a laminate type depending upon the shape of the case.
With the laminate type of electrode assembly in which several sheets of positive electrode plates, separators, and negative electrode plates are laminated, the edges of the separators protruded to the outside of the positive and negative electrode plates are typically tightly adhered to each other, and wrapped by an adhesive tape, thereby holding the shape of the electrode assembly.
However, if the rechargeable battery with a finishing structure based on the adhesive tape is used for a long period of time, the adhesion of the separators can weaken due to deterioration of the adhesive tape. As a result, the electrode assembly does not hold the initial bonding and the alignment thereof may be broken so that the bonding between the positive and negative electrode plates is weakened and the performance characteristics of the rechargeable battery are significantly deteriorated.